Portion of a vehicle rear bumper



FIG. 1 is a front perspective view of a portion of a vehicle rear bumper showing my new design, the portion of the vehicle shown in broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is another front perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a side elevational view thereof;

FIG. 6 is a bottom plan view thereof, and,

FIG. 7 is a rear elevational view thereof. 

The ornamental design for a portion of a vehicle rear bumper, as shown and described. 